What a great thread. I have really enjoyed brewing coffee in so many different ways. It seems that desperation drives us to great ingenuity. Yep....paper towels. Cowboy coffee. My dear bride Louise goes on a rampage and demands I clean out the cupboard above the stove. "Do you really need 5 different things to brew coffee?" And I guess the answer is yes. On different days I like to brew different coffees in varied ways. Yep. I like it all. Filter, press pots, my vacuum pot (love the swirling), melitta, and my 25 year old Chemex. I fold my own papers. It is way fun and quite the ritual.

So to answer in wonderful agreement with Peter. It is all good. It is all fun.

I've been thinking a bit about the approach to Chemex brewing that involves keeping the cone full of water until the desired brew time & volume and then removing the filter.

Doesn't this introduce a considerable amount of randomness to the process? In espresso percolation, where you have (correct me if I'm wrong) a constant downward percolation of water through the coffee bed, you can stop the extraction at the perfect moment and enjoy a more or less predictable composition in your demitasse.

With a pour-over, on the other hand, you've got agitation and turbulence causing coffee grinds and water to flow all over the place. What we get in the cup is a function of the likelihood of water molecules and dissolved coffee solids randomly finding their way the to edge of the paper filter and meandering through. Note that this happens throughout the cone, and not just at the bottom tip.

Essentially what I'm wondering is if, on a Chemex, we set our grind, dose and temperature to achieve a certain yield in a certain time (for instance, 650g of extract in 4 minutes and cutting the extraction at that time), with the filter kept full of hot water to keep all grinds extracting evenly, is this going to give us a predictable and repeatable result?

Put another way, if it takes 4 minutes to dissolve into the brew water those tastants and odourants that give us an ideal composition, then if we pull the filter at 4 minutes isn't the resulting brew more likely a general composition of what was dissolved by, say, 3:30? With those solids dissolved between 3:30 and 4:00 still mostly whirling about randomly inside the infusion. Would it then make sense to extend the total extraction time to 4:30? Given the element of randomness involved, wouldn't this increase the risk of over representation of those tastants that lend to bitterness and astringency?

I'm not making a statement here... I'm just curious if what I'm thinking makes any sense at all.

Well, try brewing two chemex's back to back, and then pull two shots back to back.

Which cup is more "random"? Espresso is not as controlled as your description sounds, though maybe it's because that wasn't the point of your post.

Chemex brewing is also under natural atmospheric pressure (whereas espresso is well above that). This means that randomness is probably less random than it could be in regards to cup results.

Agitation is important, sure, but pouring doesn't have to cause excessive agitation, and assuming the pouring technique is pretty consistent, I don't think this would be all that random from batch-to-batch. Within a certain batch, certainly.. but again.. how does this notion affect cup results?

So much of this is dependent on the "handle side of the chemex", and how the coffee is distributed before pouring, how the water is poured, what agitation beyond pouring is used, and on and on. Random? Sure. But not any more so than any other manual brew method (imho). Which begs the question.. why hate the Chemex?

Whether it be Chemex, Melitta, or any other manual pourover method, I never seem to be able to get by without watching the foam on the surface of the brewing water drifting from the center out towards the edges of the filter pretty dang evenly (and consistently).

Assuming that gravity and water pressure will force a more dense layer of coffee towards the bottom, and assuming that this increased density evens out the downward flow encouraged by gravity and water pressure, is it not possible that the extraction is pretty even after all?

I'm not saying that every cup is guaranteed to be perfect, but is it really the fault of the brew method?

Like most things in coffee, the best we can do is to not screw it up. Along the same lines, screwing it up is the easiest thing to do.

That having been said, I'd like to propose an alternative thread title.

Yourself: why you should hate it.

(I'm not trying to single anyone out here, as I think this is true for everyone)

Couldn't we find some analytical thought process on why we should hate just about every brew method in existence? It's easy to do. Really easy. (sure, it takes a little deep thought, but it's nothing extraordinary) What's hard is to figure out how to use these brew methods effectively.

(why do I feel like I'm just echoing things that have already been said?)

Thanks for the great points. Just to clarify my question, what I'm curious about in particular is the correct strategy and repeatability of keeping the filter cone completely full for the duration of preparation and cutting the extraction off at a given time by removing the filter.

I trust the specifics of my confusion surrounding this approach are clear enough above. To clarify, the proposed approach differs from the tradition of letting the brew water completely filter through into the bottom chamber. In the "traditional approach" (is this fair to say?), there is a more or less predictable amount of water that will be retained in the grinds and the rest will all pass through, meaning everything that is dissolved into the extract (minus the ~2ml/g retained and that retained by the paper filter) winds up in the bottom chamber.

Using the "keep the filter full the whole time" approach, a great deal of dissolved material never makes it into the bottom chamber. I'm curious what new variables need to be considered when brewing coffee this way, and how it can best be controlled.

Ian,Given that you have ExtractMojo, why don't you brew a few Chemexes as your post proposed, and take refractometer readings? You can use WxtractMojo to figure out the correlation of a particular brew strength to an extraction yield. For instance, if you use 17:1 water to grounds and want a 20% extraction, you know your brew strength should be 1.3%. If you were using a genuine 17:1 ratio, your final brew mass/volume would be 15oz per 17oz of input water (since each oz of grounds absorbs 2oz water). So let's say you make a 34oz Chemex, you'll end up with 30oz brewed coffee. Make a mark on your Chemex at the point where 30oz of hot water would rise to. Then make your Chemex as you have proposed (using more than 34oz water in order to keep the slurry full) and pull the filter when the brewed coffee reaches the 30oz line. You'll probably have to try this a few times to find the right grind. Then once you find it, repeat the process four or five times and take refractometer readings for each. If all of the batches have the same brew strength, then you know you've extracted the same amount of coffee mass each time.Good luck,Scott

Scott Rao wrote: If all of the batches have the same brew strength, then you know you've extracted the same amount of coffee mass each time.

I'm going to try this out soon, but I wanted to note that I've found the technique of keeping the slurry topped up and pulling the filter at the desired brew volume and time (I've been hitting 26oz in 4:15 with a 16.6:1 brew ratio) produces a vastly superior cup over letting the slurry drain completely. I've really enjoyed some of the coffees I've made with this method, whereas I was always a little indifferent about the results of the "drain" method.

In my earlier post in this thread, I had confessed to not having made a Chemex brew in some 3 years.

So I've made a Chemex every morning for Trish and me for the past few weeks. I have a few thoughts based on this experience.

FYI, I'm using a Ditting KR1203 grinder (yes, at home, which is what happens when you're 'between stores'), a Takahiro pouring pitcher (like this one I gave to Aaron), and an 8-cup Chemex with the big folded paper filters.

I've been frustrated for some time about the lack of controls on manual-pour brew methods. This is somewhat silly to say, but my point is that dose/throw, grind, and turbulence are really the only useful control points you have. With a Melitta or ceramic filter-holder style brew, I always crave a way to slow down the brew through the bottom of the filter, in order to extend the brew time without having to grind finer. In fact, I plugged one of the two holes on our Beehouse drippers for this reason, and I like the brew much more now.

What I'm finding by tweaking the brew every morning on the Chemex is that I am happy with a 20 oz. final volume in about 4 minutes... that's it. I am not happy with the taste results when trying to brew more than that, and I'm not happy with the taste results when trying to brew less than that.

Luke, my grind is now such that the brew is complete at just over 4 minutes (I'm at about 42 grams for the 20 oz as well... "on the button"), without having to pull the filter toward the end anymore. I'm also pre-measuring the water before putting it in my water kettle. Have you tried a japanese-style pouring pitcher?

So as far as Scott's original point is concerned, I'll stick to my original feedback: that there are perhaps reasons to "hate" the Chemex, but that most any brew method will present similar limitations. Without claiming anything "new," I think that every manual-pour system actually has a single optimal yield (brew volume)... something that I'd reckon using a refractometer would support.

Over the past couple years, I've been quietly begging folks who are involved in the creation of such things for a manual-pour filter holder with an adjustable final 'hole' aperture. This would theoretically allow one more control point with the otherwise manual system that would somewhat separate brew-time from grind/dose, allowing for an extended brew time with a coarser grind than otherwise. For those with Beehouse drippers, try plugging one of the two holes and grinding coarser. We've had great results. To my earlier point, this will depend on your target volume.

Just a little Saturday morning brain-dump, fueled by a great Chemex brew of Barismo Kenya Kiandu.

A possible hybrid (and somewhat tedious) technique would involve infusing one's coffee/water mixture for ~2 minutes in an insulated vessel like the Eva Solo (!), and then filtering through the Chemex.

We tried something similar this morning with nice results: 3 minute extraction in an insulated Zojirushi carafe, followed by filtration through the Chemex. Not very tedious at all, and the cup was better (more sweetness and less bitterness) than the one we prepared at the same time with our standard Chemex technique.

Maybe this is a stupid question, of which I have had many, but what if you make a Chemex with different grind settings. For example, have the coffee at the top of your Chemex coarse and the coffee at the bottom fine or vice versa. Pour your water with the same temps, times, and swirls. I will have to experiment.

Anyway, just wondering, this thread should never die...like Betty White.